Meanwhile, some of Boscov's other software still lives on zOS, AIX, Microsoft Windows, or DOS. As part of ongoing cost containment, though, the retailer foresees future Linux migration for a number of remaining apps, including its OLAP server, PeopleSoft financials, and probably even its point-of-sale (POS) system.

Boscov's first stepped into Linux about two years ago, with the purchase of an IBM zSeries 900 mainframe. Since then, the Reading, PA-based department store chain has reduced the headcount in its IS organization, while inching more and more of its apps into a Linux-based consolidated server environment.

"We were already paying for mainframe floor space, anyway," said Joe Poole, technical support manager at Boscov's. Essentially, the chain determined it could get more mileage out of its server real estate and IT staff by running SuSE Linux Enterprise Server as a virtual machine (VM) on the zSeries 900.

Boscov's has already avoided some software licensing costs, too. In late September, for example, company's IS department installed a GPG server for use in FTPing into the Visa and Discover payment systems. Implementing GPG in place of a commercial Pretty Good Privacy (PGP) package will save about $5,000 on licensing, Poole estimated.

"We don't necessarily perceive Linux as 'free' software, though. The VM alone cost us $45,000. We also have a contract with SuSE for software, plus a little bit of service," he noted.

Purchased in August of 2001, Boscov's 2064 model 102 z900 mainframe replaced a 9672-R44 processor. The z900 system came with 12 processors, although only four are turned on right now. Two processors are running zOS, and one of them is running VM and all the Linux instances. "The other processor is a coupling facility that links together two production logicial partitions to provide continuous operations for the zOS side," said Poole.

"We went with the z900 for additional zOS processing capability, but we also knew that a portion of the box could be reserved for zVM and Linux instances. We ordered the machine with the Integrated Facility for Linux (IFL) right from the factory, and had our first instance running the same year."

In one of the initial Linux instances, Boscov's started using Apache to serve up static Web pages, including "vendor pages" containing shipment and distribution information.

For the moment, transaction-oriented Web applications continue to operate on Microsoft's SiteServer--Commerce Edition. Boscov's, however, is now testing four instances of another e-comm server--IBM WebSphere Server--running on SuseLinux, according to Rob Schwartz, a systems programmer at Boscov's.